package cn.tedu.sp06.fb;

import cn.tedu.web.util.JsonResult;
import org.springframework.cloud.netflix.zuul.filters.route.FallbackProvider;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.stereotype.Component;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;

/**
 * @Author 作者：小龙猿
 * @Project 项目：springcloud1
 * @Time 时间：2021/9/13 11:37
 */
//网关服务调用商品服务如果出错，则执行网关的降级类
@Component
public class ItemFB implements FallbackProvider {
    //返回一个serviceId,表示当前降级类是针对哪个后台服务进行降级
    // item-service --- 只针对商品服务降级
    // * --- 对所有服务都应用这个降级类
    // null --- 等同于 *
    @Override
    public String getRoute() {
        return "item-service";
    }

    //发回给客户端的降级响应
    @Override
    public ClientHttpResponse fallbackResponse(String route, Throwable cause) {
        return new ClientHttpResponse() {
            @Override
            public HttpStatus getStatusCode() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR;
            }

            @Override
            public int getRawStatusCode() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR.value();
            }

            @Override
            public String getStatusText() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR.getReasonPhrase();
            }

            @Override
            public void close() {

            }

            @Override
            public InputStream getBody() throws IOException {
                //JsonResult --- {code:500,msg:xxx,data:null}
                String json = JsonResult.err().code(500).msg("调用商品后台服务出错").toString();
                return new ByteArrayInputStream(json.getBytes("UTF-8"));
            }

            @Override
            public HttpHeaders getHeaders() {
                HttpHeaders headers = new HttpHeaders();
                headers.add("Content-Type", "application/json;charset=UTF-8");
                return headers;
            }
        };
    }
}
